 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.properties;

 import java.io.*;
 import org.eclipse.core.internal.resources.CompatibilityMessages;
 import org.eclipse.core.internal.resources.ResourceException;
 import org.eclipse.core.internal.utils.Convert;
 import org.eclipse.core.resources.IResourceStatus;
 import org.eclipse.core.runtime.*;
 import org.eclipse.osgi.util.NLS;

 /**
  *
  */
 public class StoreKey {
     protected byte[] value = null;
     protected boolean matchPrefix = false;
     protected ResourceName resourceName = null;
     protected String qualifier = null;
     protected String localName = null;

     public StoreKey(byte[] bytes) throws CoreException {
         super();
         value = bytes;
         initializeObjects();
     }

     /*
      * The key is a full key
      */
     public StoreKey(ResourceName resourceName, QualifiedName propertyName) throws CoreException {
         super();
         this.resourceName = resourceName;
         qualifier = propertyName.getQualifier();
         localName = propertyName.getLocalName();
         initializeBytes();
     }

     /*
      * The key is a resource name -- either a full resource name
      * or a resource name prefix (for deep matching)
      * (i.e. no property name)
      */
     public StoreKey(ResourceName resourceName, boolean matchPrefix) throws CoreException {
         super();
         this.resourceName = resourceName;
         this.matchPrefix = matchPrefix;
         initializeBytes();
     }

     public String getLocalName() {
         return localName;
     }

     public QualifiedName getPropertyName() {
         return new QualifiedName(qualifier, localName);
     }

     public String getQualifier() {
         return qualifier;
     }

     public ResourceName getResourceName() {
         return resourceName;
     }

     private void initializeBytes() throws CoreException {
         try {
             ByteArrayOutputStream buffer = new ByteArrayOutputStream();
             // Step 0: the resource name prefix -- always considered in full
 writeNullTerminated(buffer, resourceName.getQualifier());
             String path = resourceName.getPath().toString();
             // Step 1: the resource path
 if (matchPrefix) {
                 // don't null terminate resource name
 writeBytes(buffer, path);
                 // If prefix matching, cannot allow other fields to be specified
 if (qualifier != null || localName != null) {
                     String message = NLS.bind(CompatibilityMessages.properties_invalidPropName, qualifier, localName);
                     throw new ResourceException(IResourceStatus.INVALID_VALUE, null, message, null);
                 }
             } else {
                 // Zero depth requires full path matching including null
 writeNullTerminated(buffer, path);
             }
             // Step 2: the name space (no prefix matching)
 if (qualifier != null) {
                 writeNullTerminated(buffer, qualifier);
                 // Step 3: the local name (no prefix matching)
 if (localName != null)
                     writeNullTerminated(buffer, localName);
             } else if (localName != null) {
                 // Specifying a local name without a qualifier is illegal
 String message = NLS.bind(CompatibilityMessages.properties_invalidPropName, qualifier, localName);
                 throw new ResourceException(IResourceStatus.INVALID_VALUE, null, message, null);
             }
             value = buffer.toByteArray();
         } catch (IOException e) {
             // should never happen
 throw new ResourceException(IResourceStatus.INTERNAL_ERROR, null, CompatibilityMessages.properties_storeProblem, e);
         }
     }

     /**
      * Assumes value bytes are fully defined -- i.e. initializing
      * from a stored key.
      */
     protected void initializeObjects() throws CoreException {
         try {
             ByteArrayInputStream stream = new ByteArrayInputStream(value);
             String prefix = readNullTerminated(stream);
             String path = readNullTerminated(stream);
             resourceName = new ResourceName(prefix, new Path(path));
             qualifier = readNullTerminated(stream);
             localName = readNullTerminated(stream);
         } catch (IOException e) {
             // should never happen
 throw new ResourceException(IResourceStatus.INTERNAL_ERROR, null, CompatibilityMessages.properties_storeProblem, e);
         }
     }

     private String readNullTerminated(ByteArrayInputStream stream) throws IOException {
         ByteArrayOutputStream buffer = new ByteArrayOutputStream();
         int b;
         while ((b = stream.read()) > 0)
             buffer.write(b);
         //should not reach end of stream without first hitting null (0) byte
 if (b == -1)
             throw new EOFException();
         return Convert.fromUTF8(buffer.toByteArray());
     }

     public byte[] toBytes() {
         return value;
     }

     //For debugging
 public String toString() {
         return new String (toBytes());
     }

     private void writeBytes(ByteArrayOutputStream stream, String value) throws IOException {
         byte[] bytes = Convert.toUTF8(value);
         stream.write(bytes);
     }

     private void writeNullTerminated(ByteArrayOutputStream stream, String value) throws IOException {
         writeBytes(stream, value);
         stream.write(0);
     }
 }

